Human Dentition Introduction Dental Anatomy Includes: 1- Nomenclature & terminology. 2- The external...
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Transcript of Human Dentition Introduction Dental Anatomy Includes: 1- Nomenclature & terminology. 2- The external...
Human Human DentitionDentition
IntroductionIntroductionDental Anatomy Includes:
1 -Nomenclature & terminology.
2 -The external morphology and internal composition of individual teeth.
3-How tooth form serves its function.
4 -The relationship of teeth to each other and to the jaw bones.
Dental Anatomy NomenclatureThe Jaws & Dental ArchesThe Jaws & Dental Arches
A. The maxilla is two bones forming
the upper jaw; they are rigidly
attached to the skull.
B. The mandible is a horse-shoe shaped bone which articulates with the skull by way of the temporo-mandibular joint the TMJ.
The Jaws and Dental Arches The Jaws and Dental Arches The Jaws and Dental Arches The Jaws and Dental Arches
Quadrants:right & left quadrants Maxillary rightMaxillary right and left.and left.
Mandibular Mandibular rightright and left.and left.
Right Left
Right Left44 QuadrantsQuadrants
Functions of Functions of TeethTeeth1- Mastication:
teeth are designed to perform this function. Incisors Canine Premolars Molars
Chisel like Cutting or
incising
Wedge like Cutting
and tearing
At least two
projections
(cusps.) Tearing
and grinding
Multiple projections
(cusps )Grinding
4- Growth of jaws:The teeth play a role in the growth of the jaws in some periods of life.
2- Appearance: - Well arranged clean teeth with proper alignment give nice appearance to the face. – Teeth give support to the facial expressions.
3- Speech:
for clear pronunciation and production of sound.
Types of TeethTypes of Teeth
Types of Types of TeethTeeth
Posterior TeethPosterior Teeth
Anterior TeethAnterior Teethfor for
cutting & tearing cutting & tearing foodfood
Anterior TeethAnterior Teeth- - UpperUpper
lateral Centrallateral Central IncisorsIncisors
CanineCanine
Anterior TeethAnterior Teeth- - Lower Lower
lateral - Centrallateral - Central IncisorsIncisors
CanineCanine
PremolarsPremolars::(in permanent (in permanent only)only)
First premolar First premolar & &
Second premolarSecond premolar
UpperUpper
LowerLower
Molars:Molars:
First & second First & second
UpperUpper
LowerLowerWisdom tooth =Third permanent molar
Types of Dentitions:Types of Dentitions:Primary & Permanent Primary & Permanent
DentitionDentition
Types of Dentitions:Types of Dentitions:I-Primary DentitionI-Primary Dentition
Deciduous ,baby, milk teeth: a. Twenty ( 20) primary teeth. b. 10 in each arch c. 5 in each quadrant
In function:2 years 12 years
I-Primary I-Primary DentitionDentition
Mixed Dentition Mixed Dentition PeriodPeriod
6 years 12 years
Eruption of
first permanent molar
Shedding of last
primary
molar
6 years eruption of first permanent molar
12 years Shedding of last primary molar
II-Permanent DentitionII-Permanent Dentition
In function:
12 years
through out life
Permanent Permanent TeethTeeth
1.1.Palmer Notation SystemPalmer Notation System
2.2.Universal SystemUniversal System
3.3.International FDI SystemInternational FDI System (two digit system)(two digit system)
Tooth Identification Tooth Identification SystemsSystems
Numbering or Coding SystemsNumbering or Coding Systems
1 - 81 - 8
1 1
1-Palmer Notation System1-Palmer Notation System
2 34
5
6
7
8
234
5
6
7
8
1 23
45
6
7
8
Right Leftfor Permanent Teethfor Permanent Teeth
8 - 18 - 1
8 - 18 - 1
1 - 81 - 8
The permanent teeth are numbered from 1-8 on each side from the
midline.
Upper right Upper left 8 7 6 5 4 3 2 1 1 2 3 4 5
6 7 8
8 7 6 5 4 3 2 1 1 2 3 4 5 6 7 8 Lower right Lower
left
Horizontal and vertical lines = symbol for the quadrant
It represents the four quadrants of the dentition
as if you are facing the patient.
In upper right In upper left
In lower right In lower left
AB
C
D
E
Palmer Notation SystemPalmer Notation Systemfor Primary Teethfor Primary Teeth
E-AE-A
E-AE-A
A-EA-E
A-EA-E
The deciduous teeth are lettered from A-E on each side from the midline
Upper right Upper left
E D C B A A B C D E
E D C B A A B C D E
Lower right Lower left
Palmer Notation SystemPalmer Notation System
2-The International Numbering System
“FDI”“FDI” Federation Dentaire InternationalFederation Dentaire International (the two digit system)The teeth are designated by using two-
digits:
a. The first digit of the code is located at the left side of the number and indicates the quadrant:
In permanent dentition In deciduous In permanent dentition In deciduous dentitiondentition
U.R. 1 2 U.L. U.R. 5 6
U.L L.R. 4 3 L. L. L.R. 8 7
L.L.
2-2-International International System System(Two Digit (Two Digit System)System) “FDI”“FDI” Federation Federation Dentaire Dentaire International International
1112131415
1617
18
21 222324
25262728
31 323334
35
36
37
38
414243
444546
47
48
1 2
34
For permanent TeethFor permanent Teeth
First Digit = quadrantFirst Digit = quadrant
Permanent teeth
18 17 16 15 14 13 12 11 21 22 23 24 25 26 27 28
48 47 46 45 44 43 42 41 31 32 33 34 35 36 37 38
b- The second digit is located at the right side of the number
and indicates the number of the tooth in the quadrant. The two digits should be pronounced separately.
Second Digit = Tooth number in the quadrantSecond Digit = Tooth number in the quadrant
For Primary TeethFor Primary Teeth
5 6
78
First Digit = quadrantFirst Digit = quadrant 5 6
78
5152
53
54
55
6162
63
64
65
71 7273
74
75
8182
84
83
85
2-2-International International System System(Two Digit (Two Digit System)System) “FDI”“FDI” Federation Federation Dentaire Dentaire International International
First Digit = quadrantFirst Digit = quadrant
Primary Teeth
55 54 53 52 51 61 62 63 64 65
85 84 83 82 81 71 72 73 74 75
First Digit = quadrantFirst Digit = quadrant
Second Digit = Tooth number in the quadrantSecond Digit = Tooth number in the quadrant
5 6
78
For Primary TeethFor Primary Teeth
Universal Universal system system
for for PermanePermanent Teethnt Teeth
Universal Universal System System
for Primary for Primary TeethTeeth
Macro & Micro-anatomy Macro & Micro-anatomy
of Teethof Teethcrown
neckroot
Surrounding Bone:Surrounding Bone:Crypt Crypt developing tooth developing tooth Socket Socket erupted tooth erupted tooth
rootroot
Anatomical Crown & Clinical Anatomical Crown & Clinical CrownCrown
Single-rooted Multi-Single-rooted Multi-rootedrooted
Micro-anatomy of TeethMicro-anatomy of Teeth
Pulp CavityPulp Cavity
1-Coronal pulp:
•Pulp chamber
•Pulp horns
2-Radicular pulp:•Root canal•Apical foramen
2-Radicular pulp:
•Root canal
•Apical foramen
Pulp Cavity in Pulp Cavity in RootRoot
Surfaces Surfaces of of Teeth Teeth
Surfaces of teeth are identified Surfaces of teeth are identified by the relationship toby the relationship to surrounding orofacial surrounding orofacial
structuresstructuresEach Each
tooth has tooth has FiveFive
surfaces:surfaces:
1.1.Facial Facial 2.2.Lingual, Lingual, 3.3.Mesial, andMesial, and4.4. Distal (proximal)Distal (proximal)5.5.Functioning surf.Functioning surf. (Incisal) occlusal, (Incisal) occlusal,
FACIAL SURFACEFACIAL SURFACE any surface on the outside any surface on the outside
(towards the face) (towards the face)
1.LABIAL is facial surface of the anterior teeth (green),
2. BUCCAL is the facial surface of the posterior teeth (blue).
Inter-proximal Inter-proximal surfaces:surfaces:
1.Facing towards the midline: MESIAL.
2. Facing away from the midline: DISTAL
Surfaces in between two Surfaces in between two teeth:teeth:
LINGUALLINGUAL The surfaces facing the tongueThe surfaces facing the tongue
PALATALPALATAL on the maxilla. on the maxilla.
palatal
Functioning Surfaces:Functioning Surfaces:chewing/biting surfaces of teeth chewing/biting surfaces of teeth
::
OCCLUSAL:OCCLUSAL: chewing surfaces of chewing surfaces of posterior teethposterior teeth
INCISAL:INCISAL: the anteriors’ the anteriors’ biting surface biting surface
Line and Point AnglesDivision into Thirds
Line angle: It is formed by the junction of two surfaces and its name is derived from both surfaces
Point angle: It is formed by the junction
of three surfaces and its name is derived from these surfaces.
Line and Point AnglesLine and Point Angles
Line Anglesof Anterior Teeth
Line AnglesLine Anglesof Posterior Teethof Posterior Teeth
Point AnglesPoint AnglesMeeting of 3 surfacesMeeting of 3 surfaces
Division into Thirds
Anatomical Anatomical Landmarks Landmarks of the Crownof the CrownDevelopmental data:Developmental data:
LobeLobe::• It is one of the primary centers of calcification and growth formed during the crown development.
• Each tooth begins to develop from four lobes or more.
•The pulp chamber has pulp horns corresponding to these lobes.
Anterior teeth
premolars
Maxillary molarsMaxillary molars
Mandibular molars
A- Crown Elevations:A- Crown Elevations:A- Crown Elevations:A- Crown Elevations:
They are three small rounded projections of
enamel present in the incisal third of
newly erupted incisors
It is the bulge on the cervical third of lingual surface of the
crown in anterior teeth
1-Mamelons1-Mamelons1-Mamelons1-Mamelons 2-Cingulum2-Cingulum2-Cingulum2-Cingulum 3-Cusps 3-Cusps 3-Cusps 3-Cusps
They are pyramidal projections on the
incisal portion of the canine and on the
occlusal surfaces of the premolars and
molars
4-Tubercle4-Tubercle4-Tubercle4-Tubercle
It is a small elevation produced by excessive formation of enamel .
Tubercle is noticed at : •the palatal surface of E & 6 •sometimes at the lingual surface of incisors over the cingulum.
N.B. Tubercle differs from cusp , it is formed of enamel only while cusp is formed of pulp horn covered by dentin and enamel.
Ridge or elevation of enamel forming the margin of the surface of a tooth;
• on mesial /distal margins of lingual surfaces anterior teeth.
• mesial & distal margins of occlusal surfaces posterior teeth
5-Ridges5-Ridges5-Ridges5-Ridges
•Linear ridges: Elevated portions of tooth run in aline named for their location
•Cervical•Incisal•Labial •Buccal •Lingual
MarginalMarginalMarginalMarginal
TriangularTriangularTriangularTriangularLinearLinearLinearLinear
Transverse RidgeTransverse Ridge
Oblique RidgeOblique Ridge
•Small , irregularly placed auxiliary grooves.•Branches from developmental grooves.•They do not denote union of primary lobes. •The third molars followed by second permanent molars are characterized by high number of supplemental grooves.
B-Crown B-Crown DepressionsDepressionsB-Crown B-Crown DepressionsDepressions
•Lingual fossa
•triangular fossae
•Central fossa
1-Developmental 1-Developmental grooves:grooves:Shallow grooves thatseparate cusps or primaryparts of teeth
Linear DepressionsLinear DepressionsLinear DepressionsLinear Depressions Irregular DepressionsIrregular DepressionsIrregular DepressionsIrregular Depressions
1-Fossa1-FossaDepression or concavity
2- Supplemental 2- Supplemental grooves:grooves:
3- Fissures3- Fissures• Found in the bottom of developmental grooves. •Result from incomplete union of the primary lobes. •Represent a fault in enamel.
Linear DepressionsLinear DepressionsLinear DepressionsLinear Depressions Irregular DepressionsIrregular DepressionsIrregular DepressionsIrregular Depressions
2- PITS:2- PITS:•b- FAULTY PIT: • Develop as a result • of incomplete formation of enamel. • It is located at the end of the buccal developmental grooves of the lower molars or palatal developmental grooves of the upper molars.